1. Field of the Invention
The present invention relates to a method of producing an ion exchanger by introducing an ion-exchanging active group into a substance containing carbon-to-carbon unsaturated double bond.
2. Description of the Prior Art
Up to now, there have been attempted many syntheses of ion exchange resins and chelate resins, but a few attempts are made practicable. For instance, as the chelate resin there are resins obtained by chloromethylation of styrene-divinylbenzene copolymer particles and subsequent iminodiacetylation thereof, resins obtained by chloromethylation of styrene-divinylbenzene copolymer particles and subsequent addition of polyethylene polyamine thereto, and the like. In any of these resins, however, styrene-divinylbenzene copolymer is used as a raw material, so that there is a restriction to the raw materials to be used and further the resulting chelate resins are expensive.
Recently, techniques for utilizing ion exchangers as vegetable culture medium and soil conditioner have been reported. For example, there are known urethane foams containing a chemically fixed ion-exchanging group, which are obtained by adding polyol modified with acid anhydride upon foaming and the like. In this way, however, there is a drawback that properties of foam and/or workability become sacrificed in accordance with an increase of an ion exchange capacity.